LONDON WATER SUPPLY.
The improvement of the Water Supply of London and its suburbs
is recognised to be one of the most important questions of the day.
The appointment of a Royal Commission to inquire into the best mode
of dealing with this grave want ; and the experience of individuals in
every district in and about London indicates the need of a prompt, and,
if possible, a complete solution of the means of providing an unfailing
supply of pure soft water, which supply should be large enough not
only to meet the wants of the present population, but should suffice for
the contingent and probable increase of population in a lon^ futurity.
It is proposed by the author to strengthen the conclusion of the
Legislature and of the public as to the absolute and prompt necessity
for this work, by reference to the experience of the past year, excep-
tional in the short rainfall in the months of April, Hay, June, July,
and the early part of August. It is further proposed to show the
pecuniary loss arising to the community from the impure character of
the water supplied, apart from its important influence on the health
of the population, on which no reliable data exist. Finally, to point
out a source from which water may be supplied in almost unlimited
quantities of excellent quality, both for sanatory and commercial
purposes, and at a cost moderate, in comparison to the benefit its use
During the last summer (1868) measurements were taken of the
quantity of water passing down the Eiver Thames at Sunbury, which
is above the points where the London "Water Companies abstract their
supply. It was then found that the yield was about 256,000,000
gallons per diem. Deducting from this amount 58,000,000 gallons —
the quantity daily abstracted by the five London Water Companies —
there would remain 198,000,000 gallons only to pass down the river
daily, so that the scouring power of the backwater would be seriously
reduced, and the silting-up of the low water channels below would be
thereby much aggravated.
In fact, owing to this abstraction and the diminished volume of
water consequent on the dry season of the past year, there has
occurred, in the low water channel of the river — particularly between
London Bridge and the sea — a diminution of depth arising from the
accumulation of silt, sewage, and other matters, which have been
principally deposited by the flood tides, and which the deficient supply
of upland water and the ebb-tide have failed to clear away. This
important matter appears to have been almost overlooked by the
authority which is usually considered as the proper guardian of navi-
gation interests — namely, the Conservancy Board. It can hardly be
credited, by those unacquainted with the fact, that the Conservancy
Board receives the greater portion of its income in the shape of an
annual payment from the five London Water Companies, for allowing
them to make the enormous abstraction of water which is required for
the daily Water Supply of London. In addition to the five companies
above alluded to, the East London Water Company, which at present
takes its supply solely from the Eiver Lea, has obtained an Act which
gives that Company the power to abstract a further 10,000,000 gallons
a day from the Thames near Sunbury ; and to effect that purpose the
works of that Company are now in course of execution.
The injurious effects upon the condition of the Thames is but one of
the many objections which may be urged against the present mode of
supply. Scientific opinions and official reports lead to the almost
general conviction that the present resources of the London Water
Companies are altogether inadequate in quantity, and the water sup-
plied by them so far defective in quality, as to lead to the production
of many sanatory evils. The point indeed remaining for consideration
is to determine the best means of enlarging the supply of pure water to
an extent commensurate with the ever-increasing demands of the vast
population occupying the metropolitan area.
The suggestion that such a supply should be derived from the
affluents of the Thames, by storing the flood waters in impounding
reservoirs constructed for the purpose, at first sight commends itself,
but in any plan yet proposed, practical objections have existed, which
have hitherto been considered insurmountable. It must also be re-
membered that any supply drawn from the Thames Basin must
inevitably be of the present hard character owing to the geological
nature of the district^ the strata being chiefly of the Chalk, Oolitic and
Lias formations. The force of this objection of hardness of water to the
Thames basin as a source of supply, will be more fully shown in a
Dismissing the Thames basin as undesirable, the nearest source to
which we can look for the "Water Supply of London is Wales. The
two principal Elvers of Wales are the Severn and the Wye, which rise
within a few miles of each other. Both of these rivers are, naturally,
capable of affording an abundant supply of pure water.
The plan proposed by the author is to collect in the watersheds of
the upper sources of the Eiver Wye, on the southern slopes of the
Plynlymnon range, an ample supply of pure, soft, and wholesome
water, and to conduct it, by means of gravitation only, to London.
The Wye basin being more thinly inhabited than the other large
river basins of England and Wales, its water is at present of less
utility, and its proposed abstraction will be of less inconvenience than
in any other case. The Thames basin above Hampton contains on the
average a population of 224 to the square mile, and the Severn above
Tewkesbury 378, whilst the Wye above Monmouth contains 97 only
to the square mile.
The only application of the water of the Wye to mechanical pur-
poses is for flour mills, of which there are very few, and these will not
be injuriously affected by the proposed plan. The fisheries which
exist on the Eiver Wye will also be protected from injury.
Owing to the rapidity of the current of the Wye and to the
absence of any important towns on the river, with the exception of
Hereford, there is but little navigation. That which does exist is
chiefly confined to the tidal portion of the river between Chepstow
and the Severn Estuary, and consequently the injury that would arise
in this respect from the abstraction of water from the Wye would be
It is this consideration which obviously renders the Eiver Wye
preferable as a source of supply to the Severn. On the latter river
are many large and important towns involving considerable internal
communication by river navigation ; furtlier, the current is less rapid,
and the abstraction of a large volume of water would be more ap-
preciable in the Severn than in the "Wye.
At the Twelfth Annual Meeting of the Canal Association held at
Birmingham in January 1869, Mr. E. Leader Williams, speaking of the
Eiver Severn, and particularly in connection with Mr. Bateman's project
for the abstraction of that which is designated as the surplus water of the
Severn to the extent of 200,000,000 gallons per day, observed ''that
nothing was known of any surplus ivater, inasmuch as the maintenance
of the estuary of the river is dependant upon the velocity and volume
of the winter floods, without which the estuary and the whole of the
lower reaches of the river would become choked with mud and silt
brought up by the far too powerful spring tides. The tendency of
these tides to choke up the lower reaches of the Severn had been
specially demonstrated during the drought of the past summer as
the deep reaches and pools near Gloucester became so filled with
deposit as to prevent navigation excepting upon the top of Spring
The upper portions of the Severn and "Wye are of the same
geological character, both being on the Silurian formation. The
physical features of these districts are also very similar, and it may
therefore safely be assumed that the water of one will be almost
precisely of the same chemical nature as that of the other. Dr.
Bobert Dundas Thomson, F.E.S., found in his analyses of the water
in the upper tributaries of the Severn, that where there was no con-
tamination from manufactories or sewage, the hardness was less than
two degrees, and that in 100,000 parts of water the total impurity
was about four parts.
According to the analyses made by the eminent chemist Dr.
Frankland, for the Begistrar-General, the average hardness of the
water supplied to London by the existing Water Companies is about
twenty degrees, and in 100,000 parts there are about twenty parts of
The water which, by the proposed plan, it is intended to bring to
London is undoubtedly of an extremely soft and pure character, and
its introduction would not only be very desirable as regards the health
of the inhabitants, but would effect a great saving both for domestic
and manufacturing purposes, especially in such articles as soap and
soda. In Glasgow, where the water is obtained from Loch Katrine,
and is very similar in character to that of the upper tributaries of the
"Wye, there are several manufactories carried on, which cannot profitably
compete in other places on account of the water not being of so soft a
quality as that of Glasgow. It is stated, on the high authority of Mr.
Bateman, the eminent engineer who constructed the Glasgow "Water-
works, that in that city there has been an annual saving in soap and
soda alone, of £36,000 on a population of 400,000 persons, by the
substitution of Loch Katrine water which is of one degree of hardness,
instead of water from the Clyde of from seven degrees to nine degrees
of hardness. As the water supplied by the London "Water Companies
is on the average of more than twenty degrees of hardness, whilst the
water proposed to be introduced is nearly equal in softness to that
of Loch Katrine, and as the population of London now exceeds
3,000,000, the probable annual saving in soap and soda, if taken
in proportion to llr. Bateman's estimate for Glasgow, would exceed
£500,000 per annum. To show the value of soft water, it may
be mentioned that at Hammersmith and the vicinity many house-
holders pay from Is. 6d. to 2s. a butt for artesian well water, which
is of a softer character, in preference to the Company's water,
which is supplied at a cost of about one-twentieth of the price
of the well water. The water supplied by the London "Water Com-
panies when used for steam boiler purposes clearly indicates its hard
quality by the solid incrustation that takes place in the boilers ; this
is very difficult to remove, and is consequently very injurious, and
increases the chances of accident.
The rainfall of the proposed district, which is very elevated, is known
to be very great, and as the configuration and position of this part of
"Wales, with reference to the Atlantic Ocean, is very similar to the
Lake district, it may safely be assumed that the rate of yield of these
districts will be nearly equal.
In the Lake district the minimum annual rainfall, which is the
proper datum to found conclusions upon, is 60 inches. If, however,
we take for the "Wye sources only 42 inches, in order that there may
be no chance of exaggeration in the calculations, we shall have, after
deducting 12 inches for evaporation and absorption, which is a fair
quantity to allow in a district such as the one in question, an available
annual rainfall of 30 inches, or 6 inches less than is taken by the
engineer for the kindred district of the Severn watershed.
The proposed gathering grounds may be divided into four districts,
the areas of which are as follows —
Ho. 1. 93,752 acres, jor 146 square miles.
„ 2. 80,181 „ „ 125
„ 3. 64,903 „ „ 102
„ 4. 42,915 „ „ 67
Total Area .. 281,761 acres or 440 square miles.
The total quantity of water which it is estimated the gathering
grounds are capable of supplying, after allowing one-fourth of the avail-
able rainfall for compensation is 393,000,000 gallons a day. However,
as the time when this large quantity of water will be required for
London is very remote, it is proposed, in the first instance, to collect
the waters in the first district only, which will yield a daily quantity
to London of 130,000,000 gallons, and to bring the other districts
successively into use, as required by the wants of the increasing
In order to economize the water to the fullest extent, it is intended
to construct impounding reservoirs in the respective watersheds, of
sufficient capacity to hold 150 days' supply, including that for compen-
sation, so that, during the longest possible drought, there will be no
diminution in the quantity delivered to London. Six impounding
reservoirs, of a total capacity of 26,250 million gallons are proposed to
be made in District "Eo. 1, and in the other districts there are suitable
sites, where reservoirs can be made when required, of proportionate
size, to store the water in the respective watersheds.
It is intended to bring the water, after allowing the matter in
mechanical suspension during floods to settle, from the impounding
reservoirs to London by means of a conduit which will have sufficient
fall to carry the water by gravitation.
The conduit will commence at the most southerly of the impounding
reservoirs in District Ko. 1, which reservoir will be placed in the Elan
Yalley, at a point about a mile and a half below Ehayader.
At the commencement it will be at a height of about 590 feet above
Ordnance Datum ; it will continue along the valley of the "Wye,
past Glasbury, Stourport, Bromsgrove, Henley-in-Arden, "Warwick,
Banbury, Tring, and Watford, to a point near Barnet, where it will
be brought into the service reservoirs at a height of 276 feet above
Wherever valleys of a considerable depth have to be crossed, the
water will be conveyed by means of inverted syphons, and in these
cases, pipes will at first be laid down, of suflScient capacity to convey
only 130,000,000 gallons a day, as the additional pipes necessary
for a further supply, can be laid down when more water is required
to supply the wants of London. In all other cases the conduit will be
of sufficient capacity to convey 230,000,000 gallons a day. Where
hills have to be penetrated, the conduit will be in tunnel, and for a
considerable portion of the remainder of its course it will be covered
where it is necessary to protect the water from contamination.
It is estimated that the total length of the conduit will be 180 miles.
The service reservoirs for which a very convenient site has been
chosen at Totteridge, near Barnet, will be at a distance of eight miles
from the Marble Arch. They will be capable of containing twenty
days supply of 130,000,000 gallons a day.
It is intended to lay down pipes from the service reservoirs to the
mains of all the existing Water Companies, by which means and
without the aid of pumping a constant supply can be afforded.
Wherever the existing pipes are not sufficiently strong to bear the
pressure that will be brought on them, they will either be replaced,
or in certain low lying districts the pressure will be reduced by
partially shutting off the water.
Water might be supplied to Birmingham and other towns which lie
near the course of conduit, and as it would be only right that these
towns, if so supplied, should contribute towards the expenses of the
undertaking, the cost to the inhabitants of London would be propor-
The cost of the first portion of the scheme to bring 130 million
gallons a day to London, the conduit (with the exception of the
inverted syphons) being made large enough to bring 230 million gallons
daily is estimated to be £7,000,000.
The additional cost for completing all the works necessary to supply
230 million gallons a day would be £2,000,000, making altogether a
total outlay of £9,000,000.
The present is considered an opportune time for carrying out an
extensive engineering operation, such as the one above referred to,
owing to the serious dearth of employment existing throughout tho
country among the class of workmen usually employed on similar
undertakings, and also to the now low price of iron and other materials.
On this ground, it is submitted the project earnestly recommends itself
to the attention of the Government, not with the view of asking the
smallest contribution from the public Exchequer, but through Govern-
ment aid, to secure the facilities necessary for obtaining legislative
sanction to such a measure at a moderate outlay.
HAMILTON H. FULTOX.
22, Geeat Geoege Steeet,